Die construction



Nov. 30, 1937. E. A. BIERQWIRVTH DIE. CONSTRUCTION Filed Aug. 3,

1936 2 Sheets-Sheet 1 av VENTOR EDWIN A. BIERWIRTH A TTORNEYS zww sa Nov. 3%, 1937.

E. A. BIERWIRTH DIE CONSTRUCTION 2 Sheets-Sheet 2 Filed Aug. 5, 1936 vFIG.2.

Flea.

INVENTOR EDWIN A. BIERWIRTH A TTORNEYS "unite arouses um cous'rnnc'rron an a. are, Detroit, inch, designer to eel 680 met-21bit, Micha corporation or were Application At 3, i936, awn No. 94bit? The invention relates to die constructions and refers more particularly to die constructions for piercing brake drums and the like to adapt the same for securement to Wheel hubs.

It is essential that-a brake drum when assembled upon a wheel hub have its braking'surface truly concentric with the axis of the wheel hub.

' It is therefore essential that the brake drum have its holes, which are used in positioning the brake drum, accurately located.

The invention has for one of its objects to provide a piercing die construction which will accurately position the brake drum or the like prior to the piercing to thereby accurately pierce this element. The invention has for another of its objects to accurately position a brake drum or the like having an annular flange with reference to a surface of the flange prior to the piercing operation. The invention has for a further ob--.

ject to support the brake drum or the like in the zone of its flange to thereby avoid distortion of the web. The invention has for these as well as other objects the novel arrangement and combinations of parts as more fully hereinafter set d forth.

In the drawings:

Figure l is a plan view, with part of the carrier removed, of a die construction showing an embodiment of my invention;

Figure 2 is a cross section on the line 2-2 of Figure 1 including the part of the earner. removed from Figure l; and

Figure 3 is a cross section on the line H of Figure 1.

As illustrated in the present instance, the die construction comprises the base i and the carrier 2, the latter being movable toward and away from the former and being guided with respect thereto by means of the pilotrods 3 at opposite sides of the die construction. it are cylinders mounted upon the base I at diagonally opposite corners and Bare pistons within these cylinders and fixed upon the upper ends of the piston rods 6, the lower ends of which are fixedly secured to the diametrically opposite arms l of the plate T]. This plate is located above the base and freely encircles the central upwardly extending annular projection 8 integral with the base. The base is preferably recessed to receive the plate with its arms.

-In the present instance, I have illustrated the die construction operable upon the brake drum 9, this brake drumbeing composite and having the annular brake flange Ill and the web Ii, the web being formed of sheet metal and the brake (or. tar ac) flange being formed of a casting imbedding the peripheral mrtion of the web.

it is an annular positioning member fixedly mounted upon the base I and having the tapered portion it extending upwardly from its base It, the inner surface of this tapered portion being cylindrical and the outer surface being tapered upwardly and toward the axis of the positioning member. it is a support engageabie with the free end of the brake flange Hi, this support being fixedly mounted on the base I and, as shown in the present instance, being 'fixedly secured upon the base it of the positioning member it. The upper end of the supporti i is located below the upper end of the tapered portion 83. it is a second annular positioning member having the upper tapered portion it, the taper of this por tion being downward and toward the axis oi the positioning member. The positioning member it has the lower cylindrical portion 16' sleeved within the positioning member 12 and fixedly secured tothe plate 1!. The positioning member 55 is guided by" the central pilot ll fixedly secured to the central projection 8 of the base and extending upwardly therefrom. The arrangement is such that the two positioning members and the pilot are concentric. it is a positioning member adapted to cooperate with the positioning members i2 and iii and comprising a transversely split resilient ring engageable with the internal brak- Y ing surface of the brake flange it. This ring has at its opposite edges the upper and lower flanges it and it respectively which extend radially inwardly and the tree edges of which are preferably formed with notches in angularly spaced zones to increase the flexibility oi the ring. The outer surface of the web of the ring is also notched in angularly spaced zones for the same purpose. The inner edges of the upper and lower flanges are preferably tapered in accordance with the tapers of the portions it and 93 respectively to provide a substantial contact. The ring is preferably held from bodily rotation by means of the key I9 between the lower flange m and the tapered portion 83 of the stationary positioning member (12.

The central pilot ill has fixedly secured to its upper end the annular die 20 having an internal diameter slightly less than that of the pilot and the annular series of annular dies 2i positioned radially outwardly of the die 20. These dies are fixed in a predetermined relation to the axes of the tapered members It and IS, the annular die central punch 22 and the annular series of punches 23 which are adapted to cooperate with the central die 2!! and the annular series of dies 2| respectively to pierce the web ll of the brake drum and to form the central hole 24 and the annular series of holes 25. The central hole 24 enables passing the brake drum over a portion of the wheel hub and the holes 25 are adapted to receive the securing means, such as bolts or studs used in securing the brake drum to the wheel hub.- Both the holes 24 and annular series of holes 25 are accurately positioned-with respect to the internal braking surface of the brake drum and assuming that the hub is accurately formed, the brake drum when mounted upon the hub will be accurately centered and secured thereto. The carrier 2 also carries the pressure plate 26 which is normally urged downwardly by the coil springs 21. This pressure plate yieldably holdsthe web ll of the brake drum against the dies 20 and 2| during the piercing operation.

In operation and assuming the carrier 2 to be in raised position and the positioning member l5 also in raised position, the ring [8 by reason of its inherent resiliency will be in a contracted position as permitted by the tapered surfaces of the positioning members I! and I2. At this time.

the ring will be slightly elevated above the position shown in Figure 2. After the brake drum has been inserted into place to rest upon the annular support ll, suitable fluid under pressure, such as compressed air, may be admitted to the upper ends of the cylinders 4 to lower the pistons 5 and to thereby lower the positioning member l5 through the intermediary of the piston rods 6 and the plates 1. The lowering of this member causes expansion of the ring I 8, both by reason of its tapered surface and also the tapered surface of the stationary positioning member l2. As a result, the ring is expanded athoth its upper and lower edges and upon complete engagement with the brake flange ID of the brake drum positively centers this brake drum. Then with the parts inthese positions, the carrier 2. is lowered, thereby piercing the central pilot hole 22 and the holes 25 for receiving the securing means, all of these holes being accurately positioned with respect to the braking surface of the brake flange.

What I claim as my invention is:

1. In a die construction for piercing the web of an element having an annular flange, the combination with a transversely split resilient ring engageable with the annular flange, oppositely tapered .members engageable with the opposite edge portions of said ring, said members being concentric and relatively movable in opposite directions to move said ring against the annular flange to thereby position the latter, and cooperating means having a predetermined relation to the axes of said tapered members for piercing the web.

2. In a die construction for piercing the web of an element having-an annularflange, the combination with a transversely split resilient ring engageable with the annular flange, oppositely of a brake drum having an annular brake flange with an internal braking surface, the combination with a transversely split resilient ring within the brake drum and engageable with the braking surface, oppositely tapered. members extending within said ring and engageable with the oppobers for piercing the web.

4. In a die construction for piercing the web of a brake drum having an annular brake flange with an internal braking surface, the combination with a transversely split resilient ring engageable with the annular flange, a stationary tapered member extending within said ring and engageable with one edge portion thereof, an axially movable tapered member extending within said ring and engageable with the other edge portion thereof, said tapered members being concentric and one being guided by the other, a support flxed with respect to said stationary tapered member and engageable with an end of the brake flange, and cboperating members having a predetermined relation to the axes of said tapered members for piercing the web.

5. In a die construction for piercing the web of a brake drum having an annular brake flange with an internal braking surface, the combinamined relation to the axes of said tapered memtion with a base having a central pilot, a transversely split resilient ring within the brake drum and engageable with the braking surface, a tapered member supported upon said base and extending within said ring and engageable with an edge portion thereof, said taperedmember being concentric with said pilot, a member flxed with respect to said base and engageable with an end of the brake flange to support the brakedrum, a second tapered member guided by said pilot and engageable with the other edge portion of said ring, means for axially moving said second mentioned tapered member with r spect to said first mentioned tapered member, die means upon said pilot and engageable with the web, and punch means cooperable with said diemeans for piercing the web.

6. In a die construction for piercing the web of an element having an annular flange, the combination with an expansible and contractible member engageable with the annular flange, tapered positioning members engageable with said flrst mentioned member, said positioning members being concentric and relatively movable to move said first mentioned member against the annular flange to thereby position the latter, and cooperating means having a predetermined relation to the axes of said positioning members for piercing the web.

'7. In a die construction for piercing the web of an element having an annular flange, the combination with a base having a central pilot, an expansible and contractible member within the element and engageable with the annular flange, relatively movable positioning members carried by said base and concentric with said pilot, said piercing members being engageable with said expansibleand contractible member, die means upon said pilot having a predetermined relation to the axes of said positioning members, and punchmeans cooperable with said die means for piercing the web of the element.

EDWIN A. BERWIBTH. 

